System and method for a fluorescence excitation and detection having distinct optical paths

A detection system for detecting fluorescence from a plurality of samples comprising:

• an illumination tube for receiving an excitation light from a light emitting diode;
• a plurality of collection optics located around and outside of an aperture in the illumination tube for collecting fluorescence, wherein the plurality of collection optics form a conical shape around the illumination tube;
• and
• a photodiode for detecting the amount of fluorescence,
• wherein the illumination tube and collection optics are disposed such that excitation light from the illumination tube and fluorescence collected by the collection optics from a sample are on the same side of the sample, and
• wherein the system does not comprise a beam splitter.

A method for detecting fluorescence comprising:

• emitting an excitation light from a light source into an illumination tube;
• directing the excitation light to an excitation filter;
• illuminating a sample with the excitation light to generate an emission light;
• and
• detecting the optical characteristics of the emission light using a plurality of collection optics located around and outside of the illumination tube, wherein the plurality of collection optics form a conical shape around the illumination tube,
• wherein the illumination tube and collection optics are disposed such that excitation light from the illumination tube and fluorescence collected by the collection optics from a sample are on the same side of the sample, and
• wherein the system does not comprise a beam splitter.